Improvement in pistons



mirii Cltric I @anni @ffm NDREWII.v SMIT-H,

or NnwYonKyN. Y.

To all w'wnt il may concern;

Be it known that I, ANDREW H. SMITH, MJD, of

` the city ct' New York, irthe county and Stateoi' New York, have invented n new and useful Improvement lin Pistons; and I do hereby declarethat the following is a full, clear, and exact description thereof, which will enable others skilled in .the art to make and use .the same, reference being had tov theaccompanying drnwingibrming part of tliis'speciication.

The figure i'sfa side view of a syringe to which in y :improvement has been attached, vparts being broken away to show the construction'.

My invention has Vfor its object to improve the construction 0f pistons- 'in' vsuoli a way that the -packing can betightened and loosened, as may be desired, wit-hout removing it from the barie1 or cylinder, or disturbing its connections, and which shnllat the same time be simple in (amstrnction, eiectirc in operation,-

and easily operated; and

It consists in the construction and combination of `vrai-ions parts, as hereinafter more fully described.

A represents vthe barrel;v it, the nozzle; and C, the cap of a syringe; Aabout -the construction of which parts tbereis nothing new. j

D is th'e'piston-rod, to the lower .end of which is attached, or upon it is iin'lned, a plate or flange,- E.

Fis the -packingwhich-- is placed upon the inner pnl-t of the rnd D, with its lower end resting against the plate or flange E.

Il'. desired, -the lower or inner end of the rod D, n pon which the packing F ispla'cenl, may be madeconical, ns shown in, the ilgnre, so that it may act as a wedge to expand the packing F when it may be drawn farther into the packing, or when lvthe said packing may bc Y pushed down upon it.

G .isla tnheor sleeve, placed upon the rod D .and

' ience. in working-tbe piston.

having a rriug, plate, orflange, H, attnelicd to or formed upon itslower or inner 'end'to rest against the ou'ter end ot' `tlie packing F. v 4

I is a nut, placed upon a screw-thread mit in the rod D at: the outer end ot' the tubular rod G, to press against the outer end of-the vsaid tubular rod l), so tha-thy tnrnngthe said nut I forward the plates E andH- will-betbiced toward each other, compressing the.- packing F longitudinally and causing it toexpand laterally, and thus iitmore closely into the barrel or cylinder A,

As the unt I is.turned back the plates E and H will be forced apart, allowing the packingto contract latemily and expalnd longitudinallygso :is to lit the` bnrrel or cylinder moreloosely.

`J isa knob, which may be formed upon or'n-ttnched to theouterend of' the tube G or-rod D for conven- Or the said piston may be workedby any other desiredmeansi.' The packing h may be made ofruhberorany other suitable' yielding material.

Haring thus described my'iurention,

I clairn as new and desire to secure by Letters Paten'trlhe combination of' the rod.l D, flange 0r plate E, tubular rod or sleeve G, ring, plate, or dnngc'H, 'and nut I, with each other,to adaptthem to expand and contract the piston pack' g, substantially as herein shown anddescribed, and for the purposes set forth.

The above specin'catlion of my invention signed by methis 31st dny' ci' October, 1870. A

ANDREW H. SMITH, D.

Witnesses T. B. Mosnnn. J uns '1. GRAHAM. 

